Granted Patent
Utility
US 4,816,236 · App. 07/134,666
Recovery of vanadium and nickel from petroleum residues
Inventor:
Harry E. Gardner
Patented Case
View Patent ↗
Granted: Mar 28, 1989
Filed: Dec 18, 1987
Inventor
Harry E. Gardner
Assignee (at issue)
U.S. Vanadium Corporation
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.